Search results for "mass"
showing 10 items of 9693 documents
Seasonality of bacterioplankton in subarctic ponds above and below treeline
2009
Large Azobenzene Macrocycles : Formation and Detection by NMR and MS Methods
2023
Azobenzene macrocycles are widely investigated as potential drug delivery systems and as part of molecular machines due to their photo-responsive properties. Herein, we detect the formation of a series of new azobenzene macrocycles that feature up to eight switchable repeating units. High-resolution mass spectrometry and ion mobility (IM) mass spectrometry experiments and 1H and diffusion-ordered spectroscopy (DOSY) NMR are used to detect the presence of the macrocycles that contain 10 to 40 aromatic rings in the gas phase and solution, respectively. The responsiveness of the Z-to-E photo-switching of the smallest of the macrocycles, exhibiting two azobenzene units and in total 10 aromatic …
Mass Spectroscopy in Penning Trap
2009
While mass spectrometry in Paul traps serves well mainly for molecular analysis in chemistry, Penning traps provide high accuracy and precision. The technique is based on the fact that the ratio of cyclotron frequencies ω c = (Q/M)B of two ions in the same magnetic field B gives directly the ratio of their masses ω c(1)/ω c(2) = M(2)/M(1). If carbon-12 as the standard of the atomic mass scale is used as reference, the mass of the ion of interest is obtained directly in atomic units. Although the cyclotron frequency is not an eigenfrequency of the Penning trap, it can be obtained from combinations of ω+, ω, and ω z as evident from the set of equations (1.31)-(1.33). In the ideal case of a pe…
Immunoaffinity purification and characterization of mitochondrial membrane-bound D-3-hydroxybutyrate dehydrogenase from Jaculus orientalis.
2008
Abstract Background The interconversion of two important energy metabolites, 3-hydroxybutyrate and acetoacetate (the major ketone bodies), is catalyzed by D-3-hydroxybutyrate dehydrogenase (BDH1: EC 1.1.1.30), a NAD+-dependent enzyme. The eukaryotic enzyme is bound to the mitochondrial inner membrane and harbors a unique lecithin-dependent activity. Here, we report an advanced purification method of the mammalian BDH applied to the liver enzyme from jerboa (Jaculus orientalis), a hibernating rodent adapted to extreme diet and environmental conditions. Results Purifying BDH from jerboa liver overcomes its low specific activity in mitochondria for further biochemical characterization of the e…
Tratamiento cognitivo-conductual de la adicción a videojuegos de rol online: fundamentos de propuesta de tratamiento y estudio de caso
2014
Resumen: El proposito de este trabajo es presentar una propuesta de tratamiento cognitivo-conductual para la intervencion en la adiccion a videojuegos. Se presenta el caso de un varon de 21 anos con problemas con el uso de los videojuegos. Se expone el procedimiento en cada una de las fases de las que consta el tratamiento, asi como los resultados de su eficacia en un estudio de caso. Despues de trece semanas de intervencion se aprecian importantes cambios en el nivel de dependencia. Los resultados muestran una disminucion significativa del tiempo de uso del ordenador y de juego, asi como una mejoria del funcionamiento personal y social del paciente. Palabras clave: Adiccion a videojuegos; …
kLa MEASUREMENT IN BIOREACTORS
2010
For accurately measuring kLa in bioreactors the dynamic pressure method (DPM) was introduced by Linek et al. (1993). In this work a simplified version of the same method is discussed. With respect to the original DPM, the simplified version greatly simplifies data treatment. In fact final constant slope observable in the usual semi-log diagram of residual driving force versus time may be simply corrected to obtain the real kLa value with negligible inaccuracy. Experimental data obtained on a lab-size stirred tank reactor confirm all model predictions, including the feature that the adoption of large pressure changes may lead to a better accuracy.
Analysis of Biomass Characteristics in MBR and MB-MBR Systems Fed with Synthetic Wastewater: Influence of a Gradual Salinity Increase
2014
The paper presents the results of a field gathering campaign carried out on two different pilot scale membrane bioreactor (MBR) systems, treating synthetic wastewater subject to a gradual increase of salinity. One was a conventional MBR system, while the other was a moving bed biofilm membrane bioreactor (MB-MBR), which combines suspended biomass and biofilm. Indeed, the presence of suspended carriers inside the bioreactor seems to give benefits due to the collisions between the circulating media and the membrane. The aim of the study was the comparison of two configurations in terms of biomass activity characterization and performance (pollutants removal and hydraulic behaviour). The resul…
Morphodynamics of river bed variation with variable bedload step length
2013
Abstract. Here we consider the 1-D morphodynamics of an erodible bed subject to bedload transport. Fluvial bed elevation variation is typically modeled by the Exner equation, which, in its classical form, expresses mass conservation in terms of the divergence of the bedload sediment flux. An entrainment form of the Exner equation can be written as an alternative description of the same bedload processes, by introducing the notions of an entrainment rate into bedload and of a particle step length, and assuming a certain probability distribution for the step length. This entrainment form implies some degree of nonlocality, which is absent from the standard flux form, so that these two express…
Problemy współczesnej genologii medialnej
2020
The paper is an attempt at clarifying the object of research into media genology, distancing itself from literary studies genology. In the era of convergence of mass media, we can observe a progress in the blurring of the border between information and journalism, which consequently changes the contemporary communicative convention. As a result, information services are often degraded and the sense of implementing ‘traditional’ indicators of mass media genres is questioned. The change of communicative convention in contemporary mass media requires, above all, the use of cultural context for its analysis, as it determines the methods of creating messages and means of receiving them. It also …
Pirandello e Gombrowicz – La presenza teatrale pirandelliana nei drammi gombrowicziani di Karol Karp (review)
2014
Veronica Chiarenza (Università degli Studi di Roma “La Sapienza”) Recensione su Pirandello e Gombrowicz - La presenza teatrale pirandelliana nei drammi gombrowicziani di Karol Karp Pirandello e Gombrowicz - La presenza teatrale pirandelliana nei drammi gombrowicziani di Karol Karp si muove nell’ambito di un dualismo e di elementi di vicinanza tra i due autori. Il volume procede attraverso un movimento “geografico” ben definito – dalla Sicilia di Pirandello alla Polonia di Gombrowicz – e concettuale – da un’immagine più ampia dei temi tipici di Pirandello sino al loro riscontro specifico in tre drammi scritti da Gombrowicz. Karp analizza il rapporto tra i due scrittori con grande diligenza e…